GATE | GATE-CS-2014-(Set-1) | Question 65

Consider a hash table with 9 slots. The hash function is ℎ(k) = k mod 9. The collisions are resolved by chaining. The following 9 keys are inserted in the order: 5, 28, 19, 15, 20, 33, 12, 17, 10. The maximum, minimum, and average chain lengths in the hash table, respectively, are

(A) 3, 0, and 1
(B) 3, 3, and 3
(C) 4, 0, and 1
(D) 3, 0, and 2


Answer: (A)

Explanation: Following are values of hash function for all keys

 5 --> 5
28 --> 1
19 --> 1  [Chained with 28]
15 --> 6
20 --> 2
33 --> 6  [Chained with 15]
12 --> 3
17 --> 8
10 --> 1 [Chained with 28 and 19]

The maximum chain length is 3. The keys 28, 19 and 10 go to same slot 1, and form a chain of length 3.
The minimum chain length 0, there are empty slots (0, 4 and 7).
Average chain length is (0 + 3 + 1 + 1 + 0 + 1 + 2 + 0 + 1)/9 = 1

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